New population-based screening indicates that 1 in 151 women have premutation alleles on the Fragile X Mental Retardation-1 (FMR1) gene (Seltzer, Baker, et al., 2012), which highlights research on the clinical phenotype of the FMR1 premutation as a significant public health priority. Emerging evidence suggests that individuals with the FMR1 premutation show deficits in pragmatic language, or the social use of language (Aziz et al., 2003; Losh, Klusek, et al., 2012). Pragmatic language skills are critical for effectie communication, and deficits in this area may lead to ineffective social interchange and difficulty managing social relationships (Bates, 1976). This proposal aims to further delineate the pragmatic language phenotype of women with the FMR1 premutation, including the possible interface between pragmatics and anxiety disorders, which are seen at elevated rates among individuals with the FMR1 premutation (Bailey et al., 2008; Roberts et al., 2009). A comparison group of mothers of children with autism spectrum disorder (ASD) will be included in order to inform disassociation across phenotypes and shed light on the range of pragmatic features that may be attributed to the biochemical effects of FMR1. Specifically, this study aims to: (1) identif specific aspects of the pragmatic language profile of mothers with the FMR1 premutation that are shared or distinct from the profile of mothers of children with ASD, and compared to controls, (2) evaluate the functional impact of pragmatic language deficits on individual and family outcomes, and (3) determine the relationship between pragmatic language and anxiety, and how it differs among mothers with the FMR1 premutation, mothers of children with ASD, and control mothers. By integrating scientific advances in neuroscience to apply a combined behavioral (both standardized and experimental) and biomarker approach, this proposal aims to clarify the nature, underlying mechanisms and functional consequences of pragmatic impairments in the FMR1 premutation. This research will inform the range of features that may be specifically linked to the biochemical effects of FMR1, and has implications for potential prevention and treatment efforts. This research will be implemented within the excellent training environment at the University of South Carolina, within the context of an expert, interdisciplinary mentorship team that has a proven history of successful collaboration. The proposed training plan focuses on: (1) developing a comprehensive understanding of the impact of anxiety on language function, (2) attaining expertise in the use of physiological and neuroendocrine markers of stress, (3) training to use eyetracking methods to index language and related processes, (4) honing skills in pragmatic language assessment and theory, and (5) sharpening professional skills such as grant writing, research ethics, etc. The proposed research and training experiences will provide the fellow with the necessary skills to develop a programmatic line of research focused on identifying profiles and predictors of communication impairments in ASD and FMR1-associated conditions.